Hamburg, June 30: Wladimir Klitschko's trainer Emanuel Steward has conceded that the IBF and WBO title holder has not met anyone with WBA world heavyweight champion David Haye's confidence and belief for almost six years.

Klitschko and Haye will fight to unify the heavyweight titles at the 57,000-seat Imtech Arena in Hamburg, Germany, on Saturday.

"Haye brings to the ring, speed, power and the mindset of a winner. He's confident and that's something Wladimir hasn't experienced since his first fight with Sam Peter [in 2005]," Steward told BBC Sport in Hamburg.

"There's a whole new energy that Haye brings that Wladimir has not had to deal with since then," he added.

Haye has been targeting a fight with Klitschko or his brother, Vitali, since ending his reign as cruiserweight champion in 2007. However, injuries to Haye or breakdowns in negotiations kept a potential bout between Haye and any of the Klitschkos on hold.

While Haye has insisted that he will retire come the end of October regardless of the result on Saturday, Klitschko says he remains undecided over when to end his career, which stands at 55 wins, with 49 knockouts, and three defeats. (ANI)